MicroBiology - CH9 Introduction to Microbial Genetics
Which best describes the flow of genetic information in a cell?
DNA encodes RNA which encodes protein
Which is true regarding DNA replication?
Each new DNA helix contains one parent strand and one newly synthesized strand
DNA sequences which encode for functional proteins
Exons
In eukaryotes, which DNA sequences encode functional protein?
Exons
In bacterial conjugation, which term refers to a recipient cell that does not have a fertility plasmid?
F-
Codons are found on tRNA, and anticodons are found on mRNA.
False
One reason mutations are so problematic is that bacterial cells have no ability to repair a mutation once it has occurred.
False
The genomes of bacteria cells, eukaryotic cells, and viruses are all about the same size.
False
The smallest unit of heredity is a chromosome.
False
Transformation is a mode of genetic recombination in which a plasmid is transferred from a donor cell to a recipient cell via a direct connection.
False
A codon contains how many nucleotides?
3
How many stop codons are contained within the genetic code?
3
Nucleotides can only be added to the ____ end of a growing chain.
3
Which template DNA sequence encodes the peptide sequence phenylalanine-leucine-aspartic acid-valine? (Look up the genetic code figure in your textbook)
3'-AAAAACCTACAT-5'
The mRNA chain is built in the ______ direction.
5' to 3'
All new DNA strands are synthesized from
5' to 3'.
A strand of mRNA is constructed in the
5, 3
Which of the following is found in prokaryotic translation but not in eukaryotic translation?
70S Ribosomes
R factors are specifically associated with which mechanism of recombination?
Conjugation
Which of the following require physical contact between two bacterial cells for DNA transfer?
Conjugation
in bacteria refers to horizontal gene transmission via pili
Conjugation
mutations are generally most harmful to cells because they cause the greatest change in the amino acid sequence of a protein.
Frameshift
Which type of mutation is generally most harmful to cells?
Frameshift mutation
The enzyme that unwinds a segment of the DNA molecule is...
Helicase
Which enzyme unzips the DNA helix prior to the start of replication?
Helicase
DNA polymerase_______is the enzyme responsible for building the DNA
III
Which is the correct order of events when a protein is made in the process of translation?
Initiation, elongation, termination
If the wild type DNA sequence reads THE CAT ATE THE BIG RAT, what type of mutation would change the sequence to THE CAT ATA ETH EBI GRA T?
Insertion
Which strand is replicated continuously without segments during DNA replication?
Leading
The enzyme involved in replicating a new DNA strand is DNA polymerase _____, and DNA polymerase _____ is involved in removing the RNA primer, closing gaps, and repairing mismatched bases.
III, I
True or false: A point mutation results from an insertion or deletion of nucleotides, and always leads to a shift of the triplet sequence from the point of mutation downstream.
False
True or false: In bacterial conjugation, all F+ donor cells are high frequency recombinant (Hfr) cells.
False
True or false: Mutations are always harmful to cells.
False
True or false: Viral genomes are always composed of either single or double stranded DNA.
False
Which enzyme synthesizes primer sequences during replication initiation?
Primase
Which type of organisms have their DNA arranged into operons?
Prokaryotes
Which of the following is incorrect about purines?
Purines are only found in DNA, not in RNA.
Which type of plasmids confer the ability of an organism to survive treatment by antibiotics?
R factors
The main enzyme responsible for transcription is
RNA polymerase.
During transcription, RNA polymerase synthesizes ______ from a(n) ______ template.
RNA; DNA
Which term refers to the transfer of genes from donor to recipient microorganisms?
Recombination
_______ refers to the transfer of genes from donor to recipient microorganisms, where the recipient strain shows a change in genetic makeup at the end.
Recombination
the transfer of genes from donor to recipient microorganisms, where the recipient strain shows a change in genetic makeup at the end.
Recombination
_____ RNA may exert control on several levels in both prokaryotes and eukaryotes.
Regulatory
What must occur prior to cell division to ensure that each new cell has a complete set of DNA chromosome(s)?
Replication
________ operons often contain genes coding for anabolic enzymes and are usually turned off by the end product of the reactions catalyzed by these enzymes.
Repressible
Which pentose sugar is found in RNA?
Ribose
Which type of mutation is due to random mistakes in replication?
Spontaneous mutation
True or false: R-factors or "resistance factors" can be shared between bacteria through conjugation to help them survive the effects of antibiotics.
True
True or false: Several codons code for the same amino acid, which is called the redundancy of the code.
True
True or false: The promoter of an operon is the location where RNA polymerase binds, whereas the operator acts as the on/off switch for transcription of the structural genes.
True
are the three stop codons within the genetic code
UAA UAG UGA
Which of the following are physical, as opposed to chemical, agents that can cause mutations?
Ultraviolet light X-rays
Which of the following are functions of RNA polymerase?
Unwinds the DNA so that transcription can take place Synthesizes an RNA molecule from DNA template
What region of DNA signals the end of a RNA transcript?
Terminator
Uracil, the nitrogenous base unique to RNA molecules, pairs with the nitrogenous base ____________
adenine
The four nitrogenous bases in DNA are , , , and .
adenine guanine cytosine thymine
What did Griffith's experiment using Streptococcus pneumoniae demonstrate?
That two different strains of S. pneumoniae transformed into a third unique and virulent strain
Nucleotide is to nucleic acid as _____________ _______________ is to protein
amino acids
How do an Hfr cell and an F+ cell differ?
The plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell.
When using an organism that has lost the ability to synthesize histidine in the Ames test, a chemical is considered a mutagen if it increases the rate of __________ mutation beyond levels that would occur spontaneously.
back
Plasmids are found in which type(s) of organisms?
bacteria fungi
Plasmids can be found in both
bacteria, fungi
involves the transfer of DNA via bacteriophages
Transduction
Which of the following is not true of conjugation?
Transfers genes for a polysaccharide capsule
Which gene transfer method involves the uptake of free DNA by competent bacterial cells?
Transformation
involves the uptake of free DNA by competent bacterial cells
Transformation
During which process is mRNA converted into a protein?
Translation
What are the two stages needed for protein synthesis?
Translation Transcription
able to shift from one part of the genome to another.
Transposons
True or false: A mutation is an alteration in the DNA sequence or content of a cell that is passed on when the cell divides.
True
In RNA, which nitrogenous base pairs with adenine?
Uracil
Which nitrogenous base is found in RNA but not found in DNA?
Uracil
True or false: During protein synthesis, many copies of a specific protein can be synthesized from a single mRNA transcript.
True
Any nitrogen-containing molecule found in DNA and RNA that provides the basis for the genetic code is a nitrogenous .
base
Initiation of transcription involves ______.
binding of RNA polymerase to promoter region
Which best describes the antiparallel orientation of strands in DNA?
One strand is 5' to 3' and the other is 3' to 5'.
DNA polymerase III is responsible for:
building the DNA chain
A mutation that causes a change in a single nucleotide in DNA
changes the corresponding nucleotide in mRNA, resulting in a different codon.
A__________is a discrete cellular structure composed of a neatly packaged DNA molecule.
chromosome
Before a bacterial cell can undergo binary fission, the ______________ must be duplicated.
chromosome
In eukaryotic cells, what cellular structure is composed of a neatly packaged DNA molecule? a.) gene. b.) genome. c.) genotype d.) chromosome. e.) histone.
chromosome
In eukaryotic cells, what cellular structure is composed of a neatly packaged DNA molecule?
chromosome Correct
A(n) _______________ is the specific sequence of 3 mRNA nucleotides, based on a DNA triplet, that encodes a particular amino acid.
codon
Each mRNA ______ codes for a particular amino acid which is then bonded with other amino acids during translation to form a protein.
codon
Elongated genomes may fit inside the minuscule volumes of a cell because of the complex ____________ of the DNA molecule.
coiling
A bacterial cell described as ________can accept soluble DNA from the surrounding environment
competent
A cell is only able to take up external genetic material through transformation if the cell is
competent
Donor and recipient bacterial cells are connected by the sex pilus during
conjugation
A _____ binds to an inactive repressor to make an active represso
corepressor
Which of the following is NOT a result of transposon activity in bacteria?
correction of ultraviolet radiation mutations
Choose all of the statements that are true about the potential impact of missense mutations.
create nonfunctional proteins produce proteins with altered function have no impact on protein function
Protein synthesis takes place in (on) the _______ of eukaryotic cells.
cytoplasm
Transcription occurs in the__________of bacteria and the _____________of yeast cells.
cytoplasm, nucleus
The purine guanine pairs with the pyrimidine
cytosine
Thymine and _______ are pyrimidines found in DNA.
cytosine
Which of the following is NOT a type of RNA?
dRNA
A frameshift is caused by __________ mutations.
deletion and insertion
Which pentose sugar is found in DNA?
deoxyribose
A nucleotide is oriented 5' or 3' depending on the location of the _______ on the strand of DNA.
deoxyribose carbons
The smallest transposons, containing only the coding region with transposase and resolvase flanked by terminal inverted repeats, are called ______.
insertion elements
Transposons that carry large blocks of genetic material that transmit drug resistance are called ______.
integrons
The DNA of a chromosome is ________ -stranded.
double
The genetic material in bacterial is
double-stranded DNA
During transcription _______, RNA polymerase moves along the DNA strand, adding complementary nucleotides to the mRNA strand.
elongation
In eukaryotic cells, gene expression is regulated in response to _____ stimuli such as nutrient and toxin levels, and also during growth and _____.
environmental; development
Which of the following occurs during translation termination?
enzymatic breaking of bond between tRNA and polypeptide chain
Proteins contribute to the phenotype of an organism by functioning as
enzymes. structural molecules.
In _____, chromosomes are wound twice around histone proteins, creating a chain of nucleosomes.
eukaryotes
Proteins that remove incorrect bases and replace them with correct ones are termed ______ repair enzymes.
excision
In bacterial conjugation, a recipient cell having no F (fertility) _______ DNA is considered F-.
factor
All mutations are harmful to the cell.
false
True or false: A cell with an integrated F factor transmits its genes at lower frequency than does a cell with a free plasmid in the cytoplasm.
false
True or false: Bacterial conjugation is a sexual process.
false
True or false: DNA polymerase converts DNA into the various types of RNA during transcription.
false
The first three events of translation in the correct order are ______, ______ , _________followed by protein folding and processing.
intiation, elongation, termination
A sequence of bases within a gene that will be transcribed, but removed from the transcript prior to translation is a/an
intron.
After a eukaryotic mRNA has been transcribed, _______ are removed.
introns
RNA molecules differ from DNA molecules because only RNA
is typically one strand of nucleotides. has ribose. does not have thymine. has uracil.
The lac repressor binds to what site within the lac operon?
lacO
The newly forming DNA strand that is discontinuously replicated in segments (Okazaki fragments) is called the __________ strand.
lagging
The __________ subunit of the ribosome is the site of peptide bond formation.
large
The _____________subunit of the ribosome holds tRNAs and catalyzes peptide bond formation by means of a ribozyme.
large
The ____________or continuous, strand is replicated without segments during DNA replication.
leading
The final sealing of nicks in a newly synthesized DNA strand is catalyzed by the enzyme ______________
ligase
The RNA form that contains the transcribed code for a protein from the original DNA strand is ____________ RNA.
mRNA
Which molecule contains the codons for the polypeptide?
mRNA
Which of the following types of RNA is the transcribed version of a structural gene in DNA, that is later read for translation into protein?
mRNA
Which of the following are directly needed in order for translation to occur?
mRNA tRNA rRNA amino acids
The three types of RNA are
mRNA, tRNA, rRNA
During eukaryotic protein synthesis, ______ ribosome(s) are used to translate mRNA that contains ______ gene(s)
many, one
A permanent inheritable alteration in the DNA sequence of a cell is a(n) ______.
mutation
A permanent, inheritable change in the genetic information is called a/an
mutation
A small number of _____ are considered beneficial in that they provide the cell with a useful change in structure or physiology.
mutations
A small number of ____________ are considered beneficial in that they provide the cell with a useful change in structure or physiology.
mutations
Genetic __________ and the variations they produce result in population changes and thus, evolution.
mutations
The ___________ bases are either purines or pyrimidines.
nitrogen
A ______ mutation results in early termination of the protein.
nonsense
A _________ mutation changes an amino-acid-producing codon into a stop codon, leading to premature termination of a protein.
nonsense
A mutation that changes a normal codon to a stop codon is called a
nonsense mutation.
The ______ DNA strand is the strand that is not directly used for transcription into mRNA during protein synthesis.
nontemplate
The basic unit of DNA structure is a(n):
nucleotide
In a protozoal or fungal cell, chromosomes are located in the
nucleus
The replication ____________ is the Y-shaped point on a replicating DNA molecule where the DNA polymerase is synthesizing new strands of DNA.
fork
Which DOES NOT occur during translation elongation?
formyl methionine is delivered to the ribosome enzymatic breaking of bond between tRNA and polypeptide chain
In protein synthesis, eukaryotic and prokaryotic cells show similarities in all of the following EXCEPT the
number of proteins encoded on a single mRNA. use of formyl-methionine as the first amino acid.
A_______ mutation results from an insertion or deletion of nucleotides in multiples of 1 or 2, leading to a shift of the triplet sequence from the point of mutation downstream.
frameshift
The most damaging type of mutation is a
frameshift mutation.
A(n) ______ is a sequence of DNA nucleotides that codes for one functional protein or RNA.
gene
Each __________ is a specific segment of the DNA with the code for production of one functional product.
gene
Random portions of host DNA are transferred by bacteriophage during
generalized transduction
random fragments of disintegrating host DNA are taken up by the phage during assembly
generalized transduction
Control mechanisms ensure that _____ are active only when their products are required.
genes
There are approximately 4,200 _______________ in the chromosome of Escherichia coli.
genes
The __________ is the sum total of genetic material in a cell.
genome
The complete set of chromosomes and genes in an organism is referred to as the .
genome
The complete set of chromosomes and genes in an organism is referred to as the __________
genome
The___________is the sum of all the genes constituting an organism's distinctive genetic makeup.
genome
The ______ is the genetic makeup of an organism that is ultimately responsible for an organism's expressed characteristics.
genotype
An organism's genetic makeup is referred to as its _____________, whereas the expression of those genes is referred to as the organism's _______________
genotype phenotype
All of the following pertain to transcription except
occurs on a ribosome in the cytoplasm.
Several DNA viruses are known to be initiators of cancers and are thus termed ____.
oncogenic
The entire genetic makeup of an organism is its _______, but the expression of certain genetic traits are known as its _________.
genotype, phenotype
All of the following are methods for detecting mutant bacteria, except __________.
gram staining
Adenine and _______ are purines found in DNA.
guanine
The purine _________ pairs with the pyrimidine cytosine.
guanine
All of the following pertain to nitrogenous bases except
guanine pairs with uracil.
The enzyme _____________unzips the DNA helix prior to the start of replication.
helicase
________is another term for genetics--the study of inheritance in living things.
heredity
When one bacterium donates DNA to another bacterium, a type of genetic recombination known as __________ has occurred.
horizontal gene transfer
The place where DNA replication is initiated is called the ______.
origin of replication
A ________ serves as the vector for transduction in bacteria.
phage
A __________ is a small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes.
plasmid
is a small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes.
plasmid
Hfr transfer involves all of the following except
plasmid gene transfer.
Extra pieces of DNA found in bacteria are called __________.
plasmids
Mutations that involve the addition, deletion or substitution of no more than a few bases are referred to as _____ mutations.
point
Mutations that involve the addition, deletion or substitution of one or a few bases are referred to as _______ mutations.
point
The characteristics resulting from the interaction of the particular genetic makeup of an organism and the environment is the __________of that organism.
phenotype
The expression of the genotype creates traits referred to as the_____________
phenotype
A DNA nucleotide is composed of a(n) _____, a(n) _____sugar, and a(n) _______base.
phosphate deoxyribose nitrogenous
Which process repairs DNA that has been damaged by ultraviolet radiation using visible light?
photoactivation
Donor and recipient bacterial cells are connected by the sex_____ during conjugation.
pilus, pili
The ____________ of the genetic code results in several codons encoding the same amino acid.
redundancy
DNA polymerase I
replaces gaps between Okazaki fragments with correct nucleotides. removes RNA primers. repairs mismatched bases.
During semiconservative _______________ the DNA is duplicated prior to binary fission.
replication
An enzyme that is named for its ability to build strands of DNA is DNA ________.
polymerase
DNA _______ is the enzyme responsible for building strands of DNA.
polymerase
DNA_____synthesizes DNA strands in the 5' to 3' direction.
polymerase
The enzymes responsible for building the DNA strand, proofreading newly produced DNA strands, and removing the RNA primer are DNA____________ I and III.
polymerase
The duplication of a cell's DNA is called
replication
The site where the old DNA strands separate and new DNA strands will be synthesized is called the
replication fork.
The initiation of transcription occurs when RNA polymerase recognizes and binds to a region of DNA called the _______
promoter
The nontranscribed region of DNA to which RNA polymerase binds to initiate transcription is called the
promoter
Structural genes code for
promotor or cellular proteins
DNA polymerase III functions to
proofread new DNA.
DNA polymerases are responsible for
proofreading/repair. building the DNA chain.
any organism that has acquired genes that originated in another organism.
recombinant
During ___________ DNA replication, the newly made double helices are composed of one parent template and one newly synthesized strand.
semiconservative
The termination of transcription involves ______.
separation of RNA from the DNA template
What type of mutation alters the base, but not the amino acid being coded for?
silent
The protein product which binds to the operator to stop transcription is called the
repressor
The _______ protein is capable of repressing an operon.
repressor or regulator
Split genes
require spliceosomes to excise introns and then join exons.
The ribosome is composed of two subunits containing ________ RNA and protein.
ribosomal or r
Two subunits of the ________ come together to perform protein synthesis
ribosome
Two subunits of the________ comprise the site of protein synthesis.
ribosome
DNA replication is said to be
semi-conservative
One role of introns is to facilitate the formation of different proteins from the same gene due to a process called alternative _________________
splicing
The _______ codon AUG of mRNA is associated with the tRNA anticodon UAC and the amino acid methionine.
start
The mRNA sequence AUG, specifying the first amino acid in protein sequences, is called the
start codon
Which of the following types of RNA delivers the amino acids to the growing peptide chain in translation?
tRNA
The ________ strand of DNA contains the order of nucleotides that are transcribed into RNA.
template
When RNA polymerase reaches the _________ site on the DNA template, the newly formed mRNA sequence is released.
termination
Translation of an mRNA sequence into a protein is terminated when the ribosome reaches a ____________
termination codon
The region of DNA that signals the end of an RNA transcript is the
terminator sequence
The pyrimidine nitrogenous bases found in DNA are cytosine and _____________
thymine
In DNA, adenine pairs with__________, whereas cytosine pairs with__________.
thymine guanine
The enzyme __________ is responsible for compacting the DNA molecule in prokaryotes.
topoisomerase
The term _____________or codon, is a sequence of 3 nucleotides in DNA that encodes an amino acid.
triplet
During DNA replication, both the leading and lagging strands are synthesized in the 5' to 3' direction.
true
During DNA replication, synthesizing new DNA from both strands requires the enzyme primase.
true
Transcription occurs in the nucleus or at the nucleoid.
true
True or false: Proteins contribute to the phenotype of an organism.
true
The nitrogenous base thymine is only found in DNA, while _____________is only found in RNA.
uracil
Unlike DNA, RNA contains the nitrogenous base ____________
uracil
Which of the following is NOT a nitrogen base found in DNA?
uracil
Vancomycin-resistant enterococci (VRE) arise when, through genetic transfer, a MRSA strain acquires the __________operon located within a______
vanA, Transposon
The native or ____________type strain describes cells that carry nonmutated DNA.
wild
During translation initiation, the _____________ ribosomal subunit binds to a specific site on the mRNA and places the start codon in correct alignment with the P site.
small
In bacteria, mRNA transcripts are first recognized by the __________ subunit of the ribosome.
small
Due to the separation of prophage DNA from the bacterial chromosome, a specific, adjacent part of the host genome is transferred during
specialized transduction
highly specific part of the host genome is regularly incorporated into the virus
specialized transduction
The development of virulent, toxin-producing bacterial strains due to the presence of a temperate prophage can occur in
specialized transduction.
A special type of RNA called ____________remove introns from eukaryotic mRNA sequences.
spliceosomes
Which is an agent that induces changes in DNA?
Mutagen
jumping genes
transposons
Which is a purine?
Guanine
In a chromosome, the dna is composed of ______ strands.
2
A DNA triplet encodes ______ mRNA codon(s) and ______ amino acid(s).
1, 1
Which is the correct order of events in transcription?
1. Initiation 2. Elongation 3. termination
To understand the structure of eukaryotic DNA, rank the following from least to most condensed.
1. double-stranded DNA 2. nucleosome 3. chromatin 4. condensed chromatin 5. supercoiled chromatin 6. chromosome
Please order the following stages of DNA replication in the proper order from first to last as it occurs in prokaryotic cells.
1. uncoiling of the parent DNA molecule 2. unzipping the hydrogen bonds between the base pairs 3. synthesis of two new DNA strands 4. two DNA molecules, each with one old and one new strand
How many replication forks are formed from opening a section of a circular DNA molecule during replication?
2
If a codon of mRNA reads 5'-UUG-3', the tRNA that delivers the amino acid to this location during translation will have an anticodon of 3'-_____-5'.
AAC
What is the main effect of ultraviolet radiation on DNA?
Abnormal bonding between adjacent pyrimidines
Which type of RNA is transcribed from a DNA template?
All types of RNA
A screening system called the __________ test is used for detecting chemicals with carcinogenic potential.
Ames
The ____ test is used to determine the carcinogenic potential of a chemical.
Ames
test is used to determine the carcinogenic potential of a chemical.
Ames
Which of the following is not true of transposons?
Are always part of plasmids
Which is true regarding adenine and guanine?
Both are purines
What is the function of tRNA?
Brings amino acids to the ribosome
If a codon for alanine is GCA, what is the anticodon?
CGU
Which component of DNA determines the 3' and 5' ends of the strands?
Carbons in the deoxyribose sugar
Introns have been shown to do which of the following?
Catalyze their own removal from a transcript through self-splicing Give rise to alternative versions of mRNA sequences from the same gene through alternative splicing Code for enzymes such as endoncleases or reverse transcriptas
The genome of a prokaryotic or eukaryotic cell includes DNA found in which sites?
Chromosomes Mitochondria Plasmids Chloroplasts
During which method of gene transfer are bacterial cells in direct contact?
Conjugation
Eukaryotic chromosomes are composed of _____.
DNA
Genes are made up of ______, a macromolecule made up of nucleotides.
DNA
The "blueprint" information for the production of proteins is permanently encoded in sections of ___________
DNA
The genome of a cell is entirely composed of the macromolecule known as ______.
DNA
The process of natural transformation was first discovered with experiments involving the Gram-positive bacterium Streptococcus pneumoniae. Which of the following statements is true about transformation of S. pneumoniae?
DNA fragments must bind to cell surface receptors prior to uptake. Transformation can be used to produce genetically engineered organisms.
The enzyme that helps pack DNA into the cell by coiling the DNA into a tight bundle is
DNA gyrase.
Okazaki fragments are attached to the growing end of the lagging strand by
DNA ligase.
What determines the order of amino acids in the primary structure of a protein?
DNA sequence of a gene
The flow of genetic information in a cell is a process starting with _________ which encodes ___________ which encodes protein.
DNA, RNA
Please select all of the characteristics of DNA to test your understanding of its chemical structure.
Deoxyribose sugar Phosphate group Nitrogenous bases
When using an organism that has lost the ability to synthesize histidine in the Ames test, which outcome would show that a chemical is a mutagen?
Enhances the rate of back-mutation to cells that can synthesize histidine
What is the name of the specialized plasmid that directs conjugation in gram-negative cells?
F factor, fertility
In bacterial conjugation, which term refers to a donor cell with a fertility plasmid located in the cytoplasm?
F+
Conjugation in gram-negative cells is directed by a plasmid called
F, fertility
What must be replicated before a cell can divide through binary fission?
Genetic material
The science of heredity is ______.
Genetics
__________is the study of the inheritance of living things.
Genetics
Which term represents all of the genetic information within a cell?
Genome
cells conjugate and transfer genetic material through proteins activated during cell adhesion instead of forming sex pili.
Gram-positive
Test your knowledge of how DNA replication works by matching the enzyme to its function.
Helicase - unzips the DNA double helix primase - synthesizes RNA primers seals nicks in DNA backbone during synthesis and repair - ligase mediates supercoiling -gyrase adds bases to growing DNA chain -
Genetic inheritance in microorganisms is best defined by which term?
Heredity
In bacterial conjugation, which type of donor has the fertility factor integrated into the chromosome?
Hfr
DNA polymerase ____ is the main enzyme involved in the building of the new DNA chain, whereas DNA polymerase ____ is involved mostly with removing the primers and repairing damaged DNA.
III/I
How does RNA differ from DNA in bacteria and eukaryotes?
In RNA, uracil replaces thymine RNA is single-stranded
What type of DNA mutation occurs as a consequence of exposure to chemical or physical mutagens?
Induced
operons are usually turned on by the substrate of the enzyme for which the structural genes code.
Inducible
Which type of operon is typically in the "off" position until the appropriate substrate is present?
Inducible operon
DNA sequences found within a gene that do not encode the protein corresponding to the gene
Introns
Which DNA sequences are found within a gene but do not encode the protein specified by that gene?
Introns
_______ are DNA sequences found within a gene that do not encode the protein corresponding to the gene
Introns
Which strand is replicated discontinuously in segments during DNA replication?
Lagging
What amino acid sequence is encoded by the DNA template sequence 3'-TACCGCGCTCTACCG-5'? (Look up the genetic code figure in your textbook.)
Methionine-Alanine-Arginine-Aspartic Acid-Glycine
Which type of mutation results in a different amino acid being incorporated into a protein?
Missense
Which of the following is not a type of bacterial DNA recombination?
Mitosis
Which of the following are chemicals that can cause mutations?
Nitrous acid Ethidium bromide Acridine dyes
Which mutation changes an amino acid producing codon into a stop codon?
Nonsense
What is the result of a point mutation that changes a template gene sequence from 3'-TACGCCATATAT-5' to 3'-TACGCCATCTAT-5'?
Nonsense mutation
In replication of DNA, the lagging strand is replicated in a discontinuous manner forming ___________fragments.
Okazaki
____________ fragments are formed during DNA replication of the lagging strand.
Okazaki
Which of the following are parts of a nucleotide in DNA?
Phosphate Nitrogenous base Deoxyribose sugar
What is a small circular segment of DNA found in the cytoplasm of prokaryotes that is capable of independent replication and usually contains nonessential genes?
Plasmid
Please choose all of the statements that are true regarding transcription and translation in prokaryotes.
Prokaryotic mRNAs often contain information from several genes in series. Transcription and translation can occur at the same time in prokaryotes. Translation occurs in the cytoplasm of prokaryotes.
RNA polymerase binds to which region of DNA to begin transcription?
Promoter
The __________ of an operon is the location where RNA polymerase binds, whereas the __________ acts as the on/off switch for transcription of the structural genes.
Promoter, operator
Which are components of an operon in a sequence of DNA?
Promoter, structural genes, operator
Which organic molecule is formed from chains of amino acids?
Protein
The DNA blueprint specifies how to make what type of macromolecule?
Proteins
Gram-positive cells conjugate and transfer genetic material through which component?
Proteins activated during cell adhesion
Which occur during posttranslational modification?
Proteins join with other proteins to form quaternary structures. Cofactors are added to proteins destined to become enzymes. Removal of formyl-methionine from the start of the polypeptide chain
Which of the following best describes translation?
RNA -> protein
The large enzyme complex involved in synthesizing RNA from a DNA template is which of the following?
RNA polymerase
Please order the following to represent the stages from beginning to end of the transcription process.
RNA polymerase binds to the promoter region on the DNA strand. RNA polymerase builds the mRNA strand based on the DNA sequence. RNA polymerase dissociates from the DNA strand at a specific sequence.
Which of the following statements is true about transposons?
Sequences that flank the site of a transposon insertion are inverted repeats. The smallest transposons are often referred to as insertion elements. Transposons can confer resistance to antibiotics. Transposons can move from a plasmid to a chromosome.
Which of the following is the genetic pattern of viral genomes?
Single or double stranded DNA or RNA
_______ mutations in DNA are caused by random mistakes in replication and not known to be influenced by any mutagenic agent.
Spontaneous
_________ mutations in DNA are caused by random mistakes in replication and not known to be influenced by any mutagenic agent.
Spontaneous
If one strand of DNA reads 5'-AAGCGTTA-3', the complementary sequence would be 5'-_______________-3'.
TAACGCTT
The complementary sequence to 5'-AAGTC-3' is 3'-______-5'.
TTCAG
Which of the following describes the primary structure of a protein?
The chain of amino acids bound by peptide bonds
Which is a nitrogenous base found in DNA?
Thymine
The nitrogenous bases found in DNA include:
Thymine Adenine Cytosine Guanine
What is the purpose of the Ames test?
To determine the carcinogenic potential of a chemical
___________ is the process of decoding DNA into messenger RNA.
Transcription
Which term, synonymous with codon, describes a trinucleotide sequence coding an amino acid in DNA?
Triplet
A mutation that changes a single nucleotide can result in a different amino acid being added into a protein.
True
DNA is the blueprint that indicates which kinds of proteins to make and how to make them.
True
DNA mutations are passed on to a cell's progeny.
True
DNA photolyase is a light-sensitive enzyme able to repair DNA damaged by ultraviolet radiation.
True
In bacteria, initiator tRNA carries formyl methionine.
True
Once a mutation in a DNA strand has been replicated into a new piece of DNA, it cannot be repaired.
True
Genes that jump from one location to another in the genome are
transposons
Transduction occurs through
a bacteriophage.
Bacterial conjugation involves
a donor cell that transfers a copy of a plasmid to a recipient cell through a pilus.
In DNA, a purine always combines with
a pyrimidine
Genetic transfer of ______ to a methicillin-resistant Staphylococcus aureus (MRSA) strain produces vancomycin resistant enterococci (VRE).
a transposon containing the vanA operon
A recombinant is any organism that has
acquired genes that originated in another organism.
Transcription elongation involves ______.
adding of nucleotides to the growing mRNA chain
Guanine and ______ are purine bases found in DNA.
adenine
The purine nitrogenous bases found in DNA are guanine and _______________
adenine
Semiconservative replication refers to
an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.
The _______ of tRNA is complementary to the mRNA codon in translation.
anticodon
The tRNA ______________is complementary to the mRNA codon.
anticodon
The ___________ of a tRNA is complementary to a ____________ of mRNA.
anticodon, codon
In DNA, the two strands of the helix are arranged in ___________ orientation.
antiparallel
Where are the chromosomes of yeast cells located?
in the nucleus
Any alteration in DNA that occurs as a consequence of exposure to chemical or physical mutagens
induced
A(n) _________ operon, such as the lac operon, is usually in the "off" position, but can be turned on when the appropriate substrate is present.
inducible
A_________ mutation results in a different amino acid being incorporated into a protein, with varying results.
missense
An agent that induces changes in DNA is
mutagen
An organism that has a mutation is called a
mutant
A permanent inheritable alteration in the DNA sequence of a cell is
mutation
The mechanisms of _____ transformation involve genes that can regulate cellular genomes and control the onset of cell division.
oncogenic
Each nucleotide is composed of
one phosphate, one nitrogenous base, one sugar.
Two components of an operon include the _____ that acts as an on/off switch, and the _____ gene sequences.
operator; structural
Gene expression in prokaryotes is regulated through _______
operons
Prokaryotic DNA is arranged into systems called _______.
operons
The site on a chromosome where DNA replication begins is called the _________ of replication.
origin
Alterations to a protein made after translation, such as removal of f-met, addition of cofactors and joining with other proteins for quaternary structure, are referred to as __________________
posttranslational
The specific order of amino acids bound to each other by peptide bonds represents the __________ structure of a protein.
primary
During replication initiation, the enzyme _______________synthesizes primer sequences.
primase
In _____ a special enzyme called a topoisomerase coils a chromosome into a tight bundle.
prokaryotes
RNA polymerase binds to the __________region to initiate transcription.
promoter
______ are functional biomolecules in cells formed from one or more long chains of amino acids.
proteins
The main effect of ultraviolet radiation on DNA is abnormal bonding between adjacent ________.
pyrimidines
The prokaryotic ribosome is composed of ______ and protein.
rRNA
The type of RNA that forms part of the ribosome is ______.
rRNA
Which type of RNA comprises ribosomal subunits?
rRNA
Please match the types of RNA with the statements that most accurately describe them to test your understanding of the different types of RNA and their basic functions in genetic expression.
transcribed version of a structural gene or genes in DNA -mRNA contains the anticodon and an amino acid binding site - tRNA forms a complex cellular structure that contributes to the process of translation - rRNA
two stages involved in protein synthesis.
transcription, translation
_______ RNA brings the amino acids to the ribosome.
transfer
The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called
transfer RNA.
During the process of _____________a competent bacterial cell may accept soluble DNA from the surrounding environment.
transformation
Griffith's experiment using Streptococcus pneumoniae demonstrated the process of _______
transformation
In Griffith's experiments with Streptococcus pneumoniae, rough nonencapsulated Streptococci were converted into smooth encapsulated Streptococci in the presence of the heat-killed smooth encapsulated Streptococci. What is the term that describes this process?
transformation
The acceptance by a bacterial cell of small DNA fragments from the surrounding environment is termed __________.
transformation
The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is
transformation.
During _______________, the information in mRNA is used to produce a protein.
translation
The ribosome, composed of rRNA and protein, is involved in the process of
translation
Which occurs during translation elongation?
translocation of ribosome formation of peptide bond between amino acids in A and P sites tRNA delivers amino acid to empty A site
